This will be a single-site study aimed at evaluating the safety, tolerability, and efficacy of quetiapine as compared to placebo in the treatment of generalized anxiety disorder. This will be an 8-week open-label sertraline trial followed by a randomized double-blind placebo-controlled, parallel-group prospective study. Participants will first receive sertraline (25-200 mg/day) for 8 weeks. Patients who remain symptomatic - are considered refractory - and meet inclusion criteria will be randomized and enter the double-blind phase. They will receive either adjunctive quetiapine (25-400 mg/day) or placebo for 8 weeks. The primary outcome measures are change in the Liebowitz Social Anxiety Scale(LSAS) and Clinical Global Impression of Improvement (CGI-I) scores. The proposed sample size is 80 subjects. Patients will be discontinued from the study if needed due to ineffectiveness or excessive side effects. Measurements of changes in efficacy and side effects will be carried out every weekly visit. Enrollment will occur over 12 months.